Humidity adjustment

ABSTRACT

Embodiments of the present invention relate to humidity adjustment. In some embodiments, a humidity adjustment device is provided. The humidity adjustment device comprises a container including a wall for defining an accommodating space. The wall includes a water separating element for separating a mixture of water vapor and liquid water, wherein the water separating element includes a sieve portion adapted to separate the mixture of water vapor and liquid water, characterized in that the sieve portion comprises holes whose sizes are in the range of 25-35 microns. Corresponding apparatus and method are disclosed as well.

FIELD OF THE INVENTION

Embodiments of the present invention generally relate to humidity adjustment, and particularly, to a device, apparatus, and method for adjusting humidity.

BACKGROUND OF THE INVENTION

Humidity adjustment is important for storage of food, plants, medical materials and the like that need a certain degree of humidity. By way of example, water loss is one of the major causes that greatly influence the freshness of fruits and vegetables during storage. To avoid water loss, it is important to control the degree of humidity and/or the transpiration rate.

Water vapor is the gaseous phase of water. Unlike other forms of water, such as liquid water, water vapor is invisible. Humidity indicates the amount of water vapor in the air. The temperatures of the atmosphere and the water surface determine the equilibrium vapor pressure. 100% relative humidity (RH) occurs when the partial pressure of water vapor is equal to the equilibrium vapor pressure.

Currently, many humidification technologies, such as evaporative humidification, ultrasonic humidification, spray technology, and the like, have been developed to adjust humidity level. However, with the existing humidification technologies, water droplets will be brought to surfaces of the fruits and vegetables, leading to growth of undesired microorganisms and other adverse effects. Furthermore, the occurrence of water droplets during storage influences the relative humidity in the air.

In another aspect, the ideal conditions for preserving various kinds of food are different. For instance, to preserve mushroom and spinach, higher RH condition (for example, about 90%) is required and the temperature is recommended to be lower (for example, lower than 15° C. but above the temperature of chilling injury).

On the other hand, the humidity condition in the air changes over seasons, from about 30% in winter to about 90% in summer. The humidity level also varies among different regions. For instance, the RH condition in southern China is generally higher than that in northern China. So it is difficult to store fruits and vegetables just in the air. Moreover, the RH condition in a refrigerator is always low, for example, about 30%. As such, the humidity condition in the refrigerator cannot meet the requirements for preserving those sensitive to water loss.

FR2517279A1 disclosed an example of prior arts which can reduce the water droplets formed on the surface of the kept fruits and vegetables. In the disclosed solution, a film made of hydrophobic material (GORETEX) and whose pore size is between 0.01-1 micron is arranged to divide the container into two parts. One is a keeping space for accommodating the fruits or vegetables. The other one forms a space filled with mixture of water vapor and water droplets. This film is permeable to water vapor but impermeable to water drops. Therefore, the water vapor can pass the film to increase the RH in the keeping space, but the water droplets can be kept outside of the keeping space. However, the pore size of the film is so small that all the water droplets are stopped from penetrating the film (see FIG. 9). As a result, the humidification efficiency is very low and RH is difficult to be adjusted.

In view of the foregoing, there is a need in the art for a solution capable of adjusting humidity for storage of food, plants, medical materials and the like efficiently, without causing undesired water droplets.

SUMMARY OF THE INVENTION

In order to address the above and other potential problems, embodiments of the present invention propose a device, apparatus, and method for adjusting humidity.

In one aspect, embodiments of the present invention provide a humidity adjustment device. The humidity adjustment device comprises a container including a wall for defining an accommodating space. The wall includes a water separating element for separating a mixture of water vapor and liquid water, wherein the water separating element includes a sieve portion adapted to separate the mixture of water vapor and liquid water, characterized in that the sieve portion comprises holes whose sizes are in the range of 25-35 microns. The water separating element is adapted to allow the water vapor and water droplets whose sizes are smaller than the holes of the sieve portion to pass through the wall and prevent the liquid water droplets whose sizes are larger than the holes of the sieve portion from passing.

Surprisingly, it is found that relatively larger water droplets (whose dimension is larger than 35 microns) are apt to wet surfaces of objects (like fruits and vegetables) and cause biological spoilage, but water droplets whose dimension is smaller than 35 microns will not. As a result, the sieve portion comprising holes of the claimed sizes can effectively avoid the formation of water droplet on the surfaces of the kept objects. In another aspect, FIG. 9 shows the particle distribution of the fine mist generated by an existing mist generator (e.g. through an ultrasonic atomization), which ranges from 5 microns to 70 microns. It can be found that a large portion of the water droplets in the mist can still pass the sieve portion, so a high humidification efficiency can be obtained. In an experiment, by choosing a suitable home ultrasonic atomization and a container of suitable size, the RH above 90% could be achieved in 10 minutes. Preferably, the size of the holes of the sieve portion is around 30 microns.

Furthermore, the sieve portion may comprise a coating comprising superhydrophobic material, e.g. nano-materials like titanium oxide available in the market. Like mentioned above, water droplets whose dimension is larger than 35 microns can wet the sieve portion and fill the holes, so the humidification efficiency is significantly decreased. However, a coating comprising superhydrophobic material can prevent the larger droplets wetting the sieve portion by “rebounding” them back, which further helps to prevent the water droplets of undesired dimension from passing.

In another aspect, embodiments of the present invention provide an apparatus comprising a humidity adjustment device according to the above aspect, and a mist generator for generating the mixture of water vapor and liquid water.

In still another aspect, embodiments of the present invention provide a method for adjusting humidity. The method comprises steps of: receiving mixture of water vapor and liquid water by a humidity adjustment device according to the above aspect; and separating the mixture of water vapor and liquid water, to allow the water vapor and water droplets whose sizes are smaller than the holes of the sieve portion to pass through the wall and prevent the liquid water droplets whose sizes are larger than the holes of the sieve portion from passing.

Embodiments of the present invention can be implemented to realize one or more of the following advantages. By providing to the container of the humidity adjustment device a water separating element having a sieve portion comprising holes of specific dimensions which allows the water vapor and water droplets of desired dimension to pass through and prevents the liquid water droplets of undesired dimension from passing, it is possible for the humidity adjustment device to adjust humidity efficiently without causing undesired water droplets. According to embodiments of the present invention, the RH condition in the humidity adjustment device can be adjusted from low level (for example, less than 30%) to high level (for example, larger than 90%). As such, freshness of food, plants, medical materials and the like that are stored by using the humidity adjustment device can be preserved in an efficient way. Accordingly, it is possible to extend the storage lifetime of the food, plants, medical materials and the like.

Other features and advantages of embodiments of the present invention will also be understood from the following description of exemplary embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, spirit and principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of one or more embodiments of the present invention are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the invention will become apparent from the description, the drawings, and the claims, wherein:

FIGS. 1A and 1B are schematic diagrams illustrating a humidity adjustment device in accordance with exemplary embodiments of the present invention, respectively;

FIG. 2 is a schematic diagram illustrating a humidity adjustment device in accordance with a further exemplary embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating a humidity adjustment device in accordance with a still further exemplary embodiment of the present invention;

FIG. 4 is a flowchart illustrating a method for adjusting humidity in accordance with exemplary embodiments of the present invention;

FIG. 5 is a schematic diagram illustrating an apparatus in accordance with an exemplary embodiment of the present invention;

FIG. 6 is a schematic diagram illustrating an apparatus in accordance with another exemplary embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating an apparatus in accordance with yet another exemplary embodiment of the present invention;

FIG. 8 is a schematic diagram illustrating an apparatus in accordance with still another exemplary embodiment of the present invention; and

FIG. 9 is a statistic diagram showing the particle distribution of the fine mist generated by an existing ultrasound mist generator.

Throughout the figures, same or similar reference numbers indicates same or similar elements.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention will now be discussed with reference to several example embodiments. It should be understood that these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the subject matter described herein, rather than suggesting any limitation on the scope of the subject matter.

The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limited to the example embodiments. As used herein, the term “water vapor” refers to the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Unlike other forms of water, water vapor is invisible. Under typical atmospheric conditions, water vapor may be continuously generated by evaporation and removed by condensation. The term “liquid water” refers to water in a liquid state, such as droplets. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

In general, embodiments of the present invention provide a humidity adjustment device, an apparatus, and a method for adjust humidity. In accordance with embodiments of the present invention, a water separating element is arranged in a wall of a container in the humidity adjustment device. The water separating element includes a sieve portion comprising holes whose sizes are in the range of 25-35 microns, preferably around 30 microns, upon receiving mixture of water vapor and liquid water, allows the water vapor and water droplets whose sizes are smaller than the holes of the sieve portion to pass through and prevents the liquid water droplets whose sizes are larger than the holes of the sieve portion from passing. In this way, the humidity adjustment device can adjust humidity with the water vapor and water droplets of desired sizes. As a result, undesired water droplets will not be caused to food, plants, medical materials and the like that are stored by using the humidity adjustment device. Now some exemplary embodiments of the present invention will be described below with reference to the figures.

Reference is now made to FIGS. 1A and 1B, where schematic diagrams illustrating a humidity adjustment device in accordance with exemplary embodiments of the present invention are shown. It should be noted that though fruits and vegetables will be described in some embodiments as discussed below, this is merely for the purpose of illustration. Embodiments of the present invention are applicable to any kinds of objects or in any situations that need humidity adjustment.

As shown in FIGS. 1A and 1B, the humidity adjustment device comprises a container 100. According to embodiments of the present invention, the container may be any type of flexible, semirigid, or rigid container. By way of example, the container may be a plastic bag, a plastic casing, and so on. According to embodiments of the present invention, the container may have various shapes, such as cuboid, sphere, ellipsoid and some other regular or irregular shapes. In the case that the container has the shape of cuboid, the container may comprise a wall, for example the wall 101, as well as a base, for example the base 103. The wall may be formed in various ways. In some embodiments, the wall may include a group of tubes or pipes. In some other embodiments, the wall may comprise multiple layers, like that in a heat exchanger. It is to be noted that the base is not essential for the container. For example, in the case that the container has the shape of sphere or ellipsoid, it only has a wall, without the base.

The wall 101 defines an accommodating space 104. The accommodating space may accommodate fruits or vegetables which need to be stored under a certain level of humidity, as shown in FIG. 1A. According to alternative embodiments of the present invention, the accommodating space may accommodate mixture of water vapor and liquid water, as shown in FIG. 1B.

As shown in FIGS. 1A and 1B, the wall 101 may include a water separating element 102 for separating mixture 105 of water vapor and liquid water. The water separating element 102 includes a sieve portion comprising holes whose sizes are in the range of 25-35 microns, preferably 30 microns, so as to allow the mixture 106 of water vapor and water droplets of desired dimension to pass through the wall 101 and prevent the liquid water droplets of undesired dimension from passing through the wall 101. The sieve portion could be for example made of nylon.

According to embodiments of the present invention, the mixture of water vapor and liquid water may be generated by a mist generator, such as a humidifier, an atomizer, and so on, which is inside or outside of the container 100. With regard to the embodiment as shown in FIG. 1A, the mixture 105 may come from a mist generator (not shown) located outside of the container 100. When the mixture 105 is processed by the water separating element 102, the water vapor and water droplets whose dimensions are smaller than the holes of the sieve portion may enter into the container 100 and the liquid water droplets whose dimensions are larger than the holes of the sieve portion may stay outside of the container 100. In an alternative embodiment, as shown in FIG. 1B, the mixture 105 of water vapor and liquid water may be generated in the container 100. By way of example, the mixture 105 may come from a mist generator (not shown) located in the container 100. After being processed by the water separating element 102, the mixture 106 of water vapor and water droplets of desired size may exist from the container 100 and the liquid water droplets of undesired size may stay inside of the container 100.

In some embodiments, the wall of the container may be partially or entirely formed by the sieve portion. As illustrated by FIGS. 1A and 1B, the water separating element 102 includes a sieve portion which forms part of the wall 101. Alternatively, the wall may be entirely formed by the sieve portion, which will be further described with regard to the embodiment of FIG. 3.

According to embodiments of the present invention, the sieve portion comprises a coating comprising superhydrophobic material. The superhydrophobic material is material having the property of superhydrophobicity. Superhydrophobicity is a physical property of a surface whereby the surface is extremely difficult to wet with water. Generally, the contact angle of a water droplet on a surface having the property of superhydrophobicity exceeds 150° and the roll-off angle is less than 10°. In the embodiments, the super-hydrophobic coating materials are nano-materials, like titanium oxide, which are available in the market. With the superhydrophobic material, the nylon or other materials of the sieve portion can be prevented from wetting and the water droplets of undesired dimension can be further prevented from passing.

In some other embodiments, the sieve portion may be a surface modified mesh that is made of metal, polymer, ceramic or other solid materials. Moreover, a coating layer may be applied on the mesh that has superhydrophobic property to prevent water droplets of undesired dimensions from going through. Since the liquid water, such as droplets, may range from several micro meters to thousands micro meters, while the diameter of the water vapor is of nano meters, almost all larger size of droplets can be blocked by the sieve portion due to the superhydrophobic properties.

According to embodiments of the present invention, the container 100 may include a supporting structure (not shown) that is adapted to support the sieve portion. For example, in the case that the sieve portion is flexible, the supporting structure may play a supporting role. The supporting structure may be implemented by any suitable technologies, either currently known or to be developed in the future, which will not be detailed here. It is to be noted that the supporting structure is optional. In some example embodiments, the sieve portion may work well without the supporting structure.

According to embodiments of the present invention, the water separating element, for example the sieve portion, may have several spatial relationships with the wall. In an embodiment, the water separating element may be arranged on a portion of the wall, as shown in FIGS. 1A and 1B. For example, the water separating element may be implemented as a layer of the wall. There may be no air gap between the wall and the water separating element. In an alternative embodiment, the water separating element may be arranged on the entire wall, as shown in FIG. 3 below. In another alternative embodiment, the water separating element may be arranged inside the container and keep a certain distance from the top of the wall, which will be described with reference to the embodiment of FIG. 2.

FIG. 2 is a schematic diagram illustrating a humidity adjustment device in accordance with a further exemplary embodiment of the present invention. The humidity adjustment device as shown in FIG. 2 may be considered as an embodiment of the humidity adjustment device described above with reference to FIG. 1A. However, it is noted that this is only for the purpose of illustrating the principles of the present invention, rather than limiting the scope thereof.

In this embodiment of FIG. 2, the humidity adjustment device comprises a container 200. The container 200 includes a wall 201 that defines an accommodating space. The wall 201 includes a water separating element 202 for receiving mixture 205 of water vapor and liquid water. As shown in FIG. 2, the water separating element 202 is located in the container and keeps a certain distance from the top of the wall. As such, the accommodating space is divided into two subspaces 208 and 209, by the water separating element 202. According to embodiments of the present invention, the water separating element 202 is comprised by the wall 201. In this regard, although the water separating element 202 is not arranged on the top of the wall 201, it still belongs to a part of the wall 201.

The mixture 205 of water vapor and liquid water may be leaded to the container 201 through a tube 204. One end of the tube 204 may be connected with an inlet on the container, and the other end of the tube 204 may be exposed to the mixture 205 or connected with an external mist generator that generates the mixture 205. In this way, the mixture 205 may enter into the container, for example, the subspace 208, through the tube 204. In the subspace 208, the water separating element 202 receives the entered mixture 205 and only allows the mixture 206 of water vapor and water droplets of desired dimension to pass through. In this way, the water vapor and water droplets of desired dimensions may enter into the subspace 209.

Water vapor may condense into undesired droplets due to a number of factors, such as temperature decrease, equilibration, and so on. For example, water vapor may condense on a surface when the surface is cooler than the dew point temperature, or when the water vapor equilibrium in air has been exceeded. In this regard, the container 200 may include a bottom 203 adapted to drain away droplets formed in the container. The bottom 203 may be perforated or grooved, such that outlet(s) or hole(s) 207 may be formed on the bottom to drain away the undesired droplets.

Reference is now made to FIG. 3, which is a schematic diagram illustrating a humidity adjustment device in accordance with a still further exemplary embodiment of the present invention. The humidity adjustment device as shown in FIG. 3 may be considered as an embodiment of the humidity adjustment device described above with reference to FIG. 1B. However, it is noted that this is only for the purpose of illustrating the principles of the present invention, rather than limiting the scope thereof.

As shown in FIG. 3, the mixture 305 of water vapor and liquid water is generated in the container 300. By way of example, the mixture 305 may come from a mist generator (not shown) located in the container 300. After being processed by the water separating element 302, the mixture 306 of water vapor and water droplets of desired dimensions may exist from the container 300 and the liquid water droplets of undesired dimensions may stay inside of the container 300.

The liquid water staying inside the container 300 may be useless and undesired. In this regard, the container 300 may include a bottom 303 adapted to drain away the liquid water. According to embodiments of the present invention, the bottom 303 may be perforated or grooved, such that outlet(s) or hole(s) 307 may be formed on the bottom to drain away the undesired droplets.

Reference is now made to FIG. 4, which is a flowchart illustrating a method 400 for adjusting humidity in accordance with exemplary embodiments of the present invention. The method 400 may be performed by the humidity adjustment device according to embodiments of the present invention, for example those discussed with respect to FIGS. 1A and 1B and FIGS. 2 to 3, as well as various modifications, adaptations to the foregoing exemplary embodiments.

The method 400 begins at step S401, where a mist of a mixture of water vapor and liquid water is received by the humidity adjustment device according to embodiments of the present invention.

At step S402, the mixture of water vapor and liquid water may be separated, such that the water vapor and water droplets of desired dimensions are allowed to pass through the wall and the liquid water droplets of undesired dimensions are prevent from passing. According to embodiments of the present invention, the mixture of water vapor and liquid water may be separated by the water separating element. In an exemplary embodiment, the mixture of water vapor and liquid water may be generated outside of the container. In this case, the water vapor and water droplets of desired dimensions enter into the container and the liquid water droplets of undesired dimensions stay outside of the container. Alternatively, the mixture of water vapor and liquid water may be generated in the container, and the water vapor and water droplets of desired dimensions exit from the container and the liquid water droplets of undesired dimensions stay inside of the container.

In accordance with embodiments of the present invention, with respect to the fact that water vapor may condense into undesired droplets, the method 400 may further comprise an optional step of draining away droplets formed in the container. For example, the droplets may be drained away through a perforated or grooved bottom of the container in the humidity adjustment device.

According to embodiments of the present invention, the humidity adjustment device may be applied in various applications. By way of example, the humidity adjustment device in accordance with embodiments of the present invention may be used by a freshness keeper, a humidifier, a refrigerator, a refrigeration house, and any suitable application either currently known or to be developed in the future, which will not be detailed here. In some embodiments, the humidity adjustment device may be installed in a closed storage box. The humidity adjustment device installed in the storage box may achieve an appropriate high humidity level, which is suitable for fruits or vegetables that prefer high moisture. Furthermore, in some embodiments, the humidity adjustment device may be implemented as an independent humidity control chamber designed for a refrigerator. The humidity level of fruits or vegetables stored in the humidity control chamber of the refrigerator may be adjusted by consumers. Still further, in some other embodiments, the humidity adjustment device may be installed in the upper layer of refrigerator, which may generate a gradient humidity level, from higher level to lower level. As such, consumers can arrange fruits or vegetables depending on the relative humidity level. Now some exemplary embodiments of the applications will be described below with reference to FIGS. 5-8.

Reference is now made to FIG. 5, which is a schematic diagram illustrating an apparatus 500 in accordance with an exemplary embodiment of the present invention. As shown in FIG. 5, the apparatus 500 comprises a humidity adjustment device including a container 100. Furthermore, apparatus 500 comprises a mist generator 501 for generating mixture of water vapor and liquid water.

According to embodiments of the present invention, the mist generator may be inside or outside of the container of the humidity adjustment device. For example, FIG. 5 shows a mist generator 501 that is outside of the container 100, which generates the mixture 105 of water vapor and liquid water. The mist generator 501 may generate mixture of water vapor and liquid water continuously or intermittently, such that the relative humidity in the container could be maintained at a required level. When the mixture 105 is processed by the water separating element 102, the liquid water of undesired dimensions may stay outside of the container 100 and the water vapor and liquid water of desired dimensions may enter into the container 100. In this way, the apparatus 500 may be implemented as a freshness keeper, for example, wherein humidity of fruits or vegetables stored in the container 100 may be well controlled.

FIG. 6 is a schematic diagram illustrating an apparatus 600 in accordance with another exemplary embodiment of the present invention. As shown in FIG. 6, the apparatus 600 comprises a humidity adjustment device including a container 200. Furthermore, apparatus 600 comprises a mist generator 601 for generating mixture of water vapor and liquid water.

Similar to the embodiment shown in FIG. 5, the embodiment of FIG. 6 shows a mist generator 601 that is outside of the container 200. When the mixture 205 generated by the mist generator 601 is processed by the water separating element 202, the liquid water of undesired dimensions may stay outside of the container 200 and the water vapor and liquid water of desired dimensions may enter into the container 200. In this way, the apparatus 600 may be implemented as a freshness keeper as well, wherein humidity of fruits or vegetables stored in the container 200 may be well controlled.

In practice, water vapor in the container 200 may condense into undesired droplets. For example, water vapor may condense on a surface when the surface is cooler than the dew point temperature, or when the water vapor equilibrium in air has been exceeded. To well control temperature and the equilibrium of water vapor inside the container 200, the apparatus 600 may optionally comprise a humidity sensor 602 adapted to monitor humidity in the container or out of the container and/or a temperature sensor 603 adapted to monitor temperature in the container or out of the container.

As shown in FIG. 6, to better control the humidity of fruits or vegetables stored in the container 200, the humidity sensor 602 and the temperature sensor 603 may monitor the humidity and temperature in the container 200, respectively. It is to be noted that the humidity sensor and the temperature sensor may monitor the humidity and temperature out of the container, which will be described with respect to embodiment of FIG. 8 below.

Alternatively, the apparatus 600 may comprise a temperature adjustment device 604 adapted to adjust the temperature associated with the container. In some embodiments, the temperature adjustment device 604 may utilize data monitored by the temperature sensor 603, to continuously or intermittently raise or lower temperature associated with the container. The temperature associated with the container may, for example, comprise temperature in the container, temperature out of the container, temperature of the wall of the container, temperature of the bottom of the container and so on.

Alternatively, the apparatus 600 may comprise a water processing device 605 adapted to collect and process liquid water prevented by the water separating element. The water processing device 605 may be implemented by any suitable technologies, either currently known or to be developed in the future, which will not be detailed here. It is to be noted that the aforesaid devices 602-605 are optional for the apparatus according to embodiments of the present invention. In some embodiments, the apparatus can be implemented without these optional devices.

FIG. 7 is a schematic diagram illustrating an apparatus 700 in accordance with yet another exemplary embodiment of the present invention. As shown in FIG. 7, the apparatus 700 comprises a humidity adjustment device including a container 100. Furthermore, apparatus 700 comprises a mist generator 701 for generating mixture of water vapor and liquid water.

The mist generator 701 may generate mixture of water vapor and liquid water continuously or intermittently, such that the relative humidity in the container could be maintained at a required level. When the mixture is processed by the water separating element 102, the water vapor and water droplets of desired dimensions may exit from the container and the liquid water droplets of undesired dimensions may stay inside of the container. In this way, fruits and vegetables may be stored in the apparatus 700 and outside of the container 100. The apparatus 700 may be implemented as a storage box, a freshness keeper, a refrigerator, a refrigeration house, and so on.

FIG. 8 is a schematic diagram illustrating an apparatus 800 in accordance with still another exemplary embodiment of the present invention. As shown in FIG. 8, the apparatus 800 comprises a humidity adjustment device including a container 300. Furthermore, apparatus 800 comprises a mist generator 801 for generating mixture of water vapor and liquid water.

Similar to the embodiment shown in FIG. 7, the embodiment of FIG. 8 shows a mist generator 801 that is inside of the container 300. When the mixture generated by the mist generator 801 is processed by the water separating element 302, the water vapor and water droplets of desired dimensions may exit from the container 300 and the liquid water droplets of undesired dimensions may stay inside of the container 300. In this way, the apparatus 800 may be implemented as a storage box, a freshness keeper, a refrigerator, a refrigeration house, and so on.

According to embodiments of the present invention, the apparatus 800 may optionally comprise a humidity sensor 802, a temperature sensor 803, a temperature adjustment device 804, and a water processing device 805. The devices 802-805 are similar to the devices 602-605 discussed above, which will not be detailed here.

It is to be noted that the above examples are shown only for illustration purpose, without suggesting any limitations on the scope of the subject matter described herein. The apparatus 500-800 may comprise other units or devices implemented by any suitable technologies, either currently known or to be developed in the future, which will not be detailed here.

Various modifications, adaptations to the foregoing exemplary embodiments of this invention may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. Any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this invention. Furthermore, other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these embodiments of the invention pertain having the benefit of the teachings presented in the foregoing descriptions and the drawings.

Therefore, it will be appreciated that the embodiments of the invention are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are used herein, they are used in a generic and descriptive sense only and not for purposes of limitation. 

1. A humidity adjustment device, comprising: a container including a wall for defining an accommodating space, the wall including a water separating element for separating a mixture of water vapor and liquid water, wherein the water separating element includes a sieve portion adapted to separate the mixture of water vapor and liquid water, wherein the sieve portion comprises holes whose sizes are in the range of 25-35 microns.
 2. The device according to claim 1, wherein the container includes a supporting structure adapted to support the sieve portion.
 3. The device according to claim 1, wherein the wall is entirely formed by the sieve portion.
 4. The device according to claim 1, wherein the sieve portion comprises a coating comprising superhydrophobic material.
 5. The device according to claim 1, wherein the container further includes a bottom adapted to drain away droplets formed in the container.
 6. The device according to claim 5, wherein the bottom is perforated or grooved.
 7. An apparatus, comprising a humidity adjustment device according to any of claim 1, further comprising a mist generator for generating the mixture of water vapor and liquid water.
 8. The apparatus according to claim 7, wherein the mist generator is outside of the container.
 9. The apparatus according to claim 7, wherein the mist generator is inside of the container.
 10. The apparatus according to claim 8, further comprising at least one of: a humidity sensor adapted to monitor humidity in the container or out of the container; and a temperature sensor adapted to monitor temperature in the container or out of the container.
 11. The apparatus according to claim 7, further comprising: a temperature adjustment device adapted to adjust temperature associated with the container.
 12. The apparatus according to claim 1, wherein the sieve portion comprises holes whose size is around 30 microns.
 13. A method for adjusting humidity, comprising: receiving mixture of water vapor and liquid water by a humidity adjustment device according to claim 1; and separating the mixture of water vapor and liquid water by the sieve portion of the water separating element.
 14. The method according to claim 13, wherein separating the mixture of water vapor and liquid water comprises: separating the mixture of water vapor and liquid water, such that the water vapor and water droplets whose sizes are smaller than the size of the holes of the sieve portion enter into the container and the liquid water droplets whose sizes are larger than the size of the holes of the sieve portion stay outside of the container.
 15. The method according to claim 13, wherein separating the mixture of water vapor and liquid water comprises: separating the mixture of water vapor and liquid water, such that the water vapor and water droplets whose sizes are smaller than the size of the holes of the sieve portion exit from the container and the liquid water droplets whose sizes are larger than the size of the holes of the sieve portion stay inside of the container. 